Stephanie Leu

UTILIZING SURFACE CHEMISTRY IN AXON/DENDRITE DIFFERENTIATION. Stephanie Leu¹, Joshua Maurer¹. Chemistry Department, Washington University, St. Louis, MO¹.

The brain contains billions of neurons that integrate incoming and outgoing signals, yet its developmental process is still unclear. Each neuron begins with many neurites that must eventually differentiate into axons or dendrites. These neurons must also manage to form synapses with each other in a network that allows chemical signals to be received an interpreted. How do these neurons come to be in specific locations and form synapses with each other? What determines whether a neurite becomes an axon instead of a dendrite?

Surface chemistry is one way to produce substrates that promote and guide neuronal growth. Self-assembled monolayers (SAM) provide a way of specifically controlling surface chemistry. We have successfully synthesized a new type of monolayer that can be photopatterned using a photolithography system to create patterns for probing axon dendrite differentiation. This SAM is composed of a photoprotected molecule that has a polyethyleneglycol head which once irradiated with 325nm light results in a carboxylic group terminated alkanethiol. Neuronal growth will only be observed on substrates ending with carboxylic acid, because of its inability to attach to the polyethyleneglycol head group. Hence, the carboxylic acid terminated alkanethiols allows for specific paths of growth.

In the future we can take this SAM and dephotoprotect certain pathways to guide neuronal growth and observe the effects of neuronal guidance cues and pattern conductance on axon/dendrite differentiation.